This invention relates to a heat retaining clothing produced with the use of an inflatable envelope consisting of a polymer film.
As heat retaining clothing, there have been well known quilted goods comprising wadding. Particularly, the quilted goods comprising wool or down of water birds as wadding have a heat retaining property of Clo value 1 to 4 and are generally considered to have the best heat retaining property. However, they are voluminous and inconvenient for carrying. Further, the heat retaining property can not be controlled. In view of these problems, Japanese Utility Model Publication No. 41,766 of 1980 discloses a garment in which each of body and sleeves is made by sewing together two air-impermeable sheets to form air chambers as a whole. However, because the surface and lining of the clothing do not have air-permeability, sweat of the wearer can be neither absorbed in the clothing nor evaporated, and accordingly the clothing is uncomfortable to wear. Further, the figure of the clothing is directly changed with the amount of air filled in the air chambers. The design of the clothing is limited. It is not practically used.
Thereafter, heat-retaining clothing comprising inflatable envelopes having a specific design are disclosed in Japanese Laid-Open Patent Publication No. 4,734 of 1984 and No. 4,735 of 1984 or U.S. Pat. No. 4,547,906. They are useful. However, since the inflatable envelope is made of a cloth treated with a synthetic or natural rubber and attached on a sheet material, the clothing is heavy, hard and uncomfatable to wear. Further, since the envelope is formed by sealing the edges with a high frequency welder which is applied on the cloth, the thickness of the coated material on the cloth becomes uneven. In order to obtain sufficient pressure resistance, the thickness of the coating layer on the cloth must be increased. Resultantly, the clothing becomes heavier and more uncomfortable to wear.
An object of the invention is to provide an improved heat retaining clothing comprising an inflatable envelope in which the heat retaining property can be controlled, particularly to provide a heat retaining clothing which is comfortable to wear and an improved durability for a long time.
Other objects and advantages of the invention will be apparent from the following detailed description.